Comminuting machine for comminuting chippable material,especially wood,into chips of predetermined size



United States Patent Inventor Wilhelm Pallmann 57 Wallstrasse 666,Zweibrucken, Germany Appl. No. 724,889

Filed Apr. 29, I968 Patented Dec. 22, 1970 Priority Apr. 27, 1967, May20, 1967 Germany No. P-29241,P-42182 COMMINUTING MACHINE FOR COMMINUTINGCHIPPABLE MATERIAL, ESPECIALLY WOOD, INTO CHIPS OF PREDETERMINED SIZE 17Claims, 4 Drawing Figs.

Int. I B02c 18/14 Field of Search 241/49, 50,

[56] References Cited UNITED STATES PATENTS 204,849 6/1878 Sherwin 241/55 794,785 7/1905 Cox 241/154 1,704,757 3/1929 Mead, Jr 241/1541,861,779 6/1932 Bornhauser 241/55 3,260,468 7/1966 Beard 241/55XPrimary ExaminerFrank T. Yost Attorney-Michael S. Striker ABSTRACT: Acomminuting machine for comminuting particulated wood or similarchippable material into chips of predetermined size wherein the materialfed into the machine passes first through rotating rough comminutingmeans and then through coaxiaily arranged fine comminuting means to bein two successive stages comminuted in a single machine into chips ofpredetermined size.

COMMINUTING MACHINE FOR COMMINUTING 'CIIIPPABLE MATERIAL, ESPECIALLYWOOD, INTO CHIPS OF PREDETERMINED SIZE BACKGROUND OF THE INVENTION Thepresent invention relates to a comminuting machine, especially to acomminuting machine for wood, in which particulated wood or similarchippable material is comminuted to chips of predetermined thickness,width and length.

Machines are known in which particulated wood or similar material iscomminuted into chips by rotating knife drums into which the material isfed. However, the chips obtained by such machines do not satisfy therequirements of uniformity as to width and length as required for themanufacture of pressboard or similar plates formed from wood chips and abinder material. Therefore, such chips are usually further disintegratedin machines such as granulators and similar mills in which the chips arefurther divided by rotating cutter drums to obtain a uniform size.

In other words to obtain chips of uniform size as to thickness, widthand length the material to be comminuted has, heretofore, been subjectedto successive comminuting processes requiring at least two separatemachines and means for transferring the material from one to the othermachine, which made this process expensive in thatit required aconsiderable initial investment, considerable space and additionaltransporting means.

It is an object of the present invention to simplify this process ofcomminuting wood particles or similar chippable material into chips ofpredetermined size and to provide a single machine for producing chipsof predetermined size from particulated wood or similar material.

It is a further object of the present invention to provide for such amachine which is composed of relatively few and simple parts so that themachine may be manufactured at reasonable cost and will stand upproperly during extended use.

SUMMARY OF THE INVENTION With these objects in view, the comminutingmachine according to the presentinvention for comminuting particulatedwoodand similar chippable material into chips of predeter- -mineddimensions as to width, length and thickness mainly comprises a housing,rotatable rough comminuting means in the housing for rough comminutingmaterial fed into the housing, feeding means comminuting with thehousing for feeding chippable material into engagement with the roughcomminuted so that the material will be rough comminuted by the latter,fine comminuting means in the housing preferably arranged coaxially withthe rough comminuting means and surrounding the latter to furthercomminute the material into chips of predetermined dimensions, andoutlet means arranged to receive said chips and ,to discharge the samefrom the housing.

The rough comminuting means preferably comprise a plurality of cuttingmeans arranged spaced from each other in a ring rotatable about an axisand extending substantially parallel to the rotating axis of the ring,and the fine comminuting means preferably comprise a plurality ofelongated cutters extending radially outwardly from segments carryingthe cutting means of the rough comminuting means to rotate therewith anda stationary curved plate at least partly surrounding the finecomminuting means coaxially therewith and having an inner serratedsurface radially spaced by a small clearance from outer edges of thecutters of the fine comminuting means. The housing of the machine isprovided with an outlet opening, the inner end thereof is preferablycovered by a sieve arranged substantially on a common cylindricalsurface with the aforementioned stationary plate of the fine comminutingmeans so that only chips of predetermined size, depending on the meshsize of the sieve, may be discharged from the machine.

The material to be comminuted is preferably fed between the knives ofthe cutter ring by a fan wheel provided in the inten'or of the cutterring and preferably rotating in a direction opposite to the direction ofrotation of the latter. Transportation of the chips out of the machinemay be enhanced by blades extending radially outwardly from the cutterring.

Instead of providing a sieve which partially surrounds the finecomminuting means, it is also possible to surround the rotating cutterring completely with a stationary plate provided at the inner surfacethereof with serrations and to form only a relatively small opening inthe plate, which extends over the whole width thereof in the region ofthe discharge opening of the machine, to thus form a discharge gap inthis plate, the width of which is preferably adjustable to avoid thusdischarge of not properly comminuted chips from the machine. Thematerial after having passed through the rough comminuting means is thusfurther disintegrated or fiberized by the cutters of the finecomminuting means and the serrations of the surrounding curved platecooperating therewith. In order to hold the percentage of undesired toofinely disintegrated material as small as possible, it is necessary toproperly correlate the size of the serrations on the stationary platewith the number of revolutions of the cutter ring.

Experiments have shown that the percentage of too fine material obtainedwith the machine according to the present invention is relatively small.This small percentage may, after the usual drying of the obtained chipsbe separated from the chips of desired size by means of a known siftingdevice.

The discharge opening of the comminuting machine according to thepresent invention may be downwardly directed, but preferably the machinehas an upwardly directed discharge socket into which the chips aretransported by the air stream produced by the vanes rotating with thecutter ring.

If the air stream thus produced is not sufficient to transport the chipsthrough a long transporting passage connected to the discharge socket ofthe machine, then an additional stream of compressed air sufficient totransport the chips in fluidized manner through a long transportingpassage may be injected into the latter.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic cross section ofone embodiment of the machine according to the present invention inwhich the discharge opening of the machine is downwardly directed;

FIG. 2 is a cross section taken along the line II-II of FIG. 1;

FIG. 3 is a cross section similar to FIG. I, but showing an otherembodiment with an upwardly directed pneumatic discharge; and

FIG. 4 is a partial cross section showing a modification of the machineas illustrated in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawing,and more specifically to FIGS. 1 and 2 of the same, it will be seen thatthe comminuting machine according to the present invention illustratedin these two FIGS. mainly comprises a housing 1 in which rough and finecomminuting means are arranged coaxially with each other. The roughcomminuting means include a cutter ring 4 composed of a plurality ofspaced carrier segments 6, defining between themselves air slotsextending in axial direction of the ring, and a plurality of cuttingknives 5 respectively carried by the segments 6, preferably adjustablyin any known manner in substantially radial direction. The finecomminuting means comprise rotatable means composed of a plurality ofelongated cutters 7 preferably adjustably fixed to substantiallyradially extending projections 6' which project outwardly from some ofthe carrier segments 6. The outer edges of the cutters 7 cooperate witha stationary curved plate 9 having an inner serrated surface arrangedcoaxially with the axis of the ring 4 andtspaced a small clearance fromthe outer edges of the cutters 7 of the fine comminuting means. As shownin FIG. 1, the serrated plate 9 extends only through a quarter of acircle about the cutter ring 4 and the remainder of the cutter ring issurrounded by a stationary sieve 8 of appropriate mesh size. It ishowever to be understood that the portions of the cutter ring which aresurrounded by the serrated plate 9 and by the sieve 8, respectively, maybe varied to a great extent and actually, as will be explained later on,the serrated plate may extend substantially over the whole circumferenceof the cutter ring to beinterrupted only by an adjustable gap fordischarge of a properly comminuted chips therethrough.

The material to be comminuted is fed through an inlet funnel 21 (FIG. 2)and an inlet opening 10 in the housing into the region of the center ofthe cutter ring, and the feeding means for feeding the material intoengagement with the cutters 5 of the rough comminuting means furtherinclude a fan wheel 2 having a plurality of fan blades 3 extending inradial direction substantially from the inner surface of the cutter ring4 towards but short of the inlet opening 10.

As best shown in FIG. 2, the blades 3 of the fan wheel are supported ona plate extending normal to the axis of the cutter ring and this plate15 is integrally connected to a hub 14 which is keyed to a shaft 12coaxially arranged with the cutter ring and projecting into the housing1 from the side thereof opposite to the inlet opening 10. A hollow shaft18 coaxially arranged with the shaft 12 supports a plate 19 normal tothe shaft axis and arranged between the plate 15 and the right sidewallof the housing, as viewed in FIG. 2, and the cutter ring 4 is supportedalong one end thereof on the aforementioned plate 19. On the oppositeside the segments 6 are connected to each other by an annular plate 20.The shaft 12 to which the fan wheel is connected may be rotated in thedirection as indicated by the arrow 13, whereas the hollow shaft 17 towhich the cutter ring 4 is connected is preferably rotated in theopposite direction as indicated by the arrow 18. The two shafts aredriven by conventional drive means not shown in the drawing. A pluralityof additional air inlet openings 11 are arranged about the materialinlet opening 10 so that additional air may be sucked into the interiorof the cutter ring 4 by the fan wheel 2, 3.

In the embodiment shown in FIGS. 1 and 2 the housing is open at thebottom to provide an outlet opening 22 for the comminuted chips.

FIG. 3 illustrated in cross section normal to the axis of the machine another embodiment which differs from the embodiment described above andillustrated in FIGS. 1 and 2 mainly in that the machine is provided withan upwardly directed outlet socket 23 which communicates at its outerend with a likewise upwardly directed transporting passage or duct 24.Furthermore, to discharge the comminuted chips pneumatically through thesocket 23 and the passage 24, the cutter ring 4 is provided withadditional fan blades 25 connected to and projecting outwardly from someof the carrier segments 6. If

the air stream produced by these fan blades 25 should not be sufficientto transport the chips through the passage 24, additional air injectormeans 26 may be provided, as schematically indicated in dash lines inFIG. 3, and constructed in a known manner to inject a stream ofcompressed air in upward direction into the passage 24. In themodification shown in FIG. 3, the serrated plate 9 surroundsthree-quarters of the circumference of the cutter ring 4 and onlyone-quarter of the cutter ring is encompassed by a sieve 8 arranged atthe inner end of the discharge socket 23 on a common cylindrical surfacewith the serrated plate 9.

, FIG. 4 illustrates a further modification in which the ser- 3 ratedplate 9 surrounds nearly the whole cutter ring and is interrupted onlyat the inner end of the discharge socket 23 of reduced cross section.The size of the discharge opening 26 through which chips may bedischarged from the machine may be adjusted by a sliding plate 27slidable in appropriate grooves formed in the housing of the machine. Inthis case a sieve may be completely eliminated.

The operation of the machine above described will be obvious from thedescription. Particulated wood or similar chippable material is fedthrough the inlet funnel 21 into the region of the axis of the machineand during rotation of the fan wheel 2, 3 in direction as indicated bythe arrow 13 and rotation of the cutter ring 4 in the opposite directionas indicated by the arrow 18, the material is passed first through therough cutting means to be roughly comminuting and then through the finecomminuting means whereby the material is further comminuted into chipsof predetermined size by the cooperation of the cutters 7 and theserrated plate 9. The material thus comminuted passes, in the machineshown in FIG. 1, in downward direction through the sieve 8, and in themachine shown in FIG. 3, the comminuted chips are pneumaticallytransported in upward direction through the outlet socket 23 and thetransporting passage 24.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofcomminuting machines for comminuting particulated wood and similarchippable material into chips of predetermined dimensions differing fromthe types described above.

While the invention has been illustrated and described as embodied in acomminuting machine for comminuting particulated wood and similarchippable material into chips of predetermined dimensions in which thematerial is successively passed through rough and fine comminuting meansarranged coaxially with each other, it is not intended to be limited tothe details shown, since various modifications and structural changesmay be made without departing in any way from the spirit of the presentinvention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims.

Iclaim:

1. A comminuting machine for comminuting particulated wood and similarchippable material into chips of predetermined dimensions as to width,length and thickness comprising, in combination, a housing; rotatablerough comminuting means in said housing for rough comminuting materialfed into said housing; feeding means communicating with said housing forfeeding chippable material into engagement with said rough comminutingmeans so that the material will be rough comminuted by the latter; finecomminuting means in said housing arranged to continuously receive therough comminuted material from said rough comminuting means to furthercomminute the material into chips of predetermined dimensions, saidrough and said fine comminuting means comprising cutting means havingcutting edges for cuttingly engaging said chippable material; and outletmeans arranged to receive said chips and to discharge the same from saidhousing.

2. A comminuting machine as defined in claim 1, wherein said rough andsaid fine comminuting means are arranged coaxially with each other abouta common axis.

3. A comminuting machine as defined in claim 1, wherein said roughcomminuting means are arranged within said fine comminuting means andwherein said feeding means are arranged to feed the material to becomminuted into the interior of said rough comminuting means.

4. A comminuting machine as defined in claim 3, wherein said finecomminuting means comprise rotatable means fixedly connected to saidrough comminuting means for rotation therewith and stationary meanscarried by said housing coaxial with said common axis and at least inpart a surrounding said rotatable means of said fine comminuting means.

5. A comminuting machine as defined in claim 3, wherein said feedingmeans comprise a fan wheel coaxially arranged within said roughcomminuting means.

6. A comminuting machine as defined in claim 3, wherein said roughcomminuting means comprise a plurality of said cutting means which arearranged spaced from each other extending substantially parallel to saidaxis in a ring coaxially with said common axis. v

7. A comminuting machine as defined in claim 6, wherein said pluralityof cutting means comprise a plurality of carrier segments arrangedspaced from each other in said ring to define a plurality of axiallyextending air slots, and a cutting knife carried by each of saidsegments.

8. A comminuting machine as defined in claim 7, wherein said cuttingmeans of said fine comminuting means comprise rotatable means composedof a plurality of elongated cutters fixed to and projectingsubstantially radially outwardly from said carrier segments and inlongitudinal direction substantially parallel to said axis, and a curvedstationary plate at least partly surrounding said fine comminuting meanscoaxially arranged therewith and having an inner serrated surfaceradially spaced by a small clearance from outer edges of said cutters.

9. A comminuting machine as defined in claim 8, wherein said feedingmeans comprise a fan wheel coaxially arranged within said roughcomminuting means and means for rotating said fan wheel in a directionopposite to the direction of rotation of said rough comminuting means.

10. A comminuting machine as defined in claim 9, wherein said fan wheelhas a plurality of fan blades extending toward said common axis andhaving inner edges radially outwardly spaced from said axis, and whereinsaid feeding means further includes passage means extending through saidhousing into the space between said inner edges of said fan blades.

11. A comminuting machine as defined in claim 9, and including aplurality of blades connected to said carrier seg ments and extending insubstantially radial outward direction.

12. A comminuting machine as defined in claim 8, wherein said stationaryplate extends only partly around said axis and wherein said outlet meanscomprise a downwardly directed outlet opening in said housing and asieve arranged in the region of said outlet opening.

13. A comminuting machine as defined in claim 12, wherein said sieve isarranged substantially on a common cylindrical surface with said plateand completely surrounding with the latter the rotating means.

14. A comminuting machine as defined in claim 8, wherein said outletmeans comprise an outlet socket communicating with said housing.

15. A comminuting machine as defined in claim 14, wherein said socketprojects in upward direction from said housing, a transporting passagecomminuting with an outer end of said socket, and passage meanscommunicating with said transporting passage for feeding air underpressure in upward direction into the latter.

16. A comminuting machine as defined in claim 8, wherein said housing isprovided with an outlet opening, and wherein said plate extendssubstantially about the whole circumference of said rotatable means ofsaid fine comminuting means except for a gap located in the region ofsaid outlet opening.

17. A comminuting machine as defined in claim 16 and including means foradjusting the size of said gap.

